Along with the Wii, we also tore down the "Wii Remote" controller featuring a 3-axial acceleration sensor and Bluetooth access between the main unit, and the "Nunchuk" controller, which is used in conjunction with the Wii Remote. As we expected after seeing the main board inside the Wii, the number of components was extremely limited and their finishing seemed to be aimed at low-cost manufacturing.
It may be attributed to assumption of rough, shaky use, but Wii Remote was designed with focus on shock resistance. Electrode brackets in battery box are symbolic. Negative electrode brackets are designed to tightly hold battery cells using springs.
Wii Remote's substrate. Upper is controller's rear side (battery box side) and bottom is front side (buttons side). Broadcom Corp.'s Bluetooth chip can be found in center of substrate. This is just about behind batteries. Three-axial acceleration sensor that detects controller's move sits on substrate's buttons side, next to A button (red arrow). This location is more on top side than Wii Remote's overall gravity center. It may be intentional the sensor is set off controller's central axis. This 3-axial acceleration sensor was Analog Devices, Inc.'s product.
Wii Nunchuk also features 3-axial acceleration sensor. This was a product by STMicroelectronics of Italy and France.